Heating unit for hair curling



y 0, 1966 s. L. MGNAIR 3,250,895

HEATING UNIT FOR HAIR CURLING Filed Aug. 21, 1964 INVENTOR. fiamae/ A, Mc/Va/r United States Patent Office 3,250,895 HEATING UNIT FOR HAIR CURLING Samuel L. McNair, Long Beach, Calif., assignor to The Songrand Corporation, Kansas City, Mo., a corporation of Missouri Filed Aug. 21, 1964, Ser. No. 391,082 Claims. (Cl. 219222) This application is a continuation-in-part of my copending application Serial No. 322,875, filed November 12, 1963.

This invention relates to hair curling apparatus and deals more particularly with that typev of apparatus in which the reshaping and setting of the hair is accomplished largely as a result of heat applied during the reshaping of the hair.

In the aforementioned application there is disclosed hair curling apparatus involving hand manipulated heating units. which are heated by inserting them into a console or cabinet designed to cooperate with the heating units to bring them up to the desired temperature, following which the heating units are removed as required and individually inserted within a cooperating hair curl roller disposed in the users hair and about which a lock of hair is wrapped.

One of the principal objects of the present invention is to provide a heating unit of the general type disclosed in the aforementioned application and which is individually self-governing in the sense of holding its maximum temperature to that which is considered safe and desirable, thereby to guard eifectively against generation of temperatures in the unit undesirably higher than those necessary to obtain curling of the hair. In the instant invention, the amount of heat generated by and stored within the heating element or unit is controlled by means locatedwithin and integral with the unit thus providing an especially accurate control function which contributes greatly to safe use of the curling apparatus.

Another important object of the invention is to provide a heating unit in which protection against failure of operation of the heat governing means is provided. In the heating unit according to the invention, heating beyond the limit to be maintained by the control means will result in interruption of the electrical circuit providing the energy for heating. A particular feature of the invention in this respect resides in the manner of constructing the unit in order to achieve this result in the economical fashion.

A further object of the invention is to provide a heating unit having self-contained thermostatic means for limiting the temperature to which the unit is heated and in which visually perceivable means are provided by which the user can tell at a glance whether the heating unit is at the proper temperature for use.

Still another object of the invention is to provide means operable in conjunction with one or more of said heating units to produce heat in said units and confine it substantially thereto until a given unit is removed for use.

Among other objects of the invention are the provision of apparatus for curling the hair in which the heater unit is conveniently and safely heated and can be easily shifted from the place Where heated to operative relationship with the hair; which does not at any time bring electrical cords or wiring into contact with or close to the users head; and which is economical to manufacture and if necessary, repair.

Other and further objects of the invention, together with the features of novelty appurtenant thereto will appear in the course ofthe following description.

Patented May 10, 1966 In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals indicate like parts in the various views;

FIG. 1 is a perspective view of a console or cabinet equipped with two heating units, one of which is shown as removed from the console, all constructed in accord ance with a preferred embodiment of the invention;

FIG. 2 is a fragmentary lengthwise central sectional View through the assembly of FIG. 1, both heating units in this view being shown as operatively inserted in the console;

FIG. 3 is an enlarged central longitudinal section through a heating unit constructed in accordance with the invention;

FIG. 4 is a side elevational view, taken from the right hand side of FIG. 4, and broken away to indicate in- .terrupted length of the internal heating element, the ceramic plug and indicator lamp;

FIG. 5 is a sectional view taken along line 55 of FIG. 3 in the direction of the arrows; and

FIG. 6 is an exploded perspective view of the preferred embodiment of the heating unit and cooperating hair curl roller and clamp utilized therewith.

In the preferred embodiment, this invention incorporates the use of heating units which are operatively connected to a console and become heated by electrical power supplied to the console. The heating units individually store heat within themselves, which heat is then transferred to hair wrapped around a hair curl roller when the heating unit is removed from the console and inserted into the center of the roller.

The number of rollers and dififerent sizes thereof, along with the number of heating units and different sizes there of, needed for effective operation will depend upon the particular circumstances. However I have found that a set of approximately 25 rollers of two different sizes in combination with a console including four different heating units of two diiferent sizes is very satisfactory for use in a womans dressing room. Similarly, the ensemble could include only one heating unit and roller adpated to be carried in the purse of the user and then used for touchup purposes.

Referring now to the drawings, I have shown in the preferred embodiment a console and two heating units of two different sizes. More particularly, the console includes a housing ltl'to which is supplied electrical power from a conventional wall plug 11. The power supply to the console is controlled by a standard off-on switch 12 located in the top wall thereof. Formed within the housing 10 are two cylindrical cavities 13 and 14 (see FIG. 2) which open through the top of the housing to receive heating units indicated generally by the arrow 15. As mentioned above and as :will be described in greater detail hereinafter, the heating units 15 cooperate with the electrical components within the console in such manner that when the heating units are inserted into the cavities 13 or 14, the heating units are heated up to a predetermined temperature. As will be further described below, the heating units 15 each have masses of material, preferably ceramic, located Within them, which material has the specific function-among other functions-of absorbing heat while the heating unit is in the console and storing that heat for later use.

Still describing further the general method of use of the inventive subject matter, prior to the time that the heater members 15 have become heated, the user will wrap locks of her hair around numerous hair curl rollers of the general type illustrated at 16 in FIG. 6, and clamp the hair to the roller 16 by the resilient, encircling clamp 17. Further details as to the clamp and roller can be found in my aforementioned copending application. Then the user selects and grasps the proper heating unit, removes it from the console and inserts it into the center of the roller 16. With the heating unit in position inside the roller, the heat which is stored in the heating unit will radiate generally radially outwardly into the hair wrapped around the roller. Of course, it will be understood that the curling rollers 16 will be of different sizes to correspond with the differing sizes of the heating units.

Referring now to FIG. 2 through 5, the preferred construction of a heating unit 15 will be described in detail. In order to facilitate the description and understanding of the preferred embodiment of the heating unit, it will be described in the generally vertical position shown in FIG. 3. However, naturally such terms as upper and lower and top in the specification and claims are merely used as a frame of reference and are not to be taken as a limitation of the orientation with respect to the earth, of the different portions of embodiments of the invention.

Forming the outside shell of each heating unit 15 is a cylindrical hollow body 18 made of electrical and heat conducting material, preferably a material such as aluminum. The body 18 is substantially closed at its lower end and is provided with a drawn nipple 18a thereon, providing a reduced diameter passageway 18b.

Located within the cylindrical tube 18 at the lower end thereof is a ceramic insulator 19 having an exterior configuration generally the same as that of the lower end nected to and assists in supporting ah electrically conductive central pin-like contact 23, which depends down through and beyond the ceramic insulator 19. It will be noted that insulator 19 and pin-like contact 23 which is inserted into an appropriate bore in the core serves to center the lower end of the core with respect to the tube 18.

At the upper end of the core 21 is a cap 24 which is of generally the same character of the lower end cap 22, being formed of electrically conductive material and sleeved over the upper end of the core. The upper end of the resistance wire 21 is electrically connected with this cap. The cap 24 seats within a recess or socket 25a formed in the lower end of a ceramic plug or insert 25 which fits within the tube 18 above the core.

The plug 25 is circular in plan, having a diameter close to, but just slightly less, than the inside diameter of the tube 18 so that it can easily be inserted into the open upper end of the tube. Both the lower and upper surfaces of the plug are respectively subdivided by transverse diametric grooves 26 and 27. The bottoms of the grooves are defined by the opposite sides of a web-like section 28 which is provided intermediate its ends with an offset or jogged portion substantially at the center thereof.

Disposed in the lower groove 26 of the plug 25 is a conductor strip or bar 29 having a free end in a firm engagement with the top of the upper end cap 24. In the preferred construction the strip 29 isso formed that its free end normally projects below the upper end surface of the cavity 250. In this way it is'assured that during assembly when the plug is brought down on top of the core 21 with the end cap in the cavity, positive contact will be made between the strip and the end of the cap. The other end of the strip 29 is anchored to the plug by the electrically conductive rivet 30. The rivet 30 extends through web portion 28 and also ties down and anchors one end of a bimetal thermostatic element 31.. which is disposed in the base of the upper groove 27.

In its normal unstressed condition, the thermostat element 31 hasv closed contact with the upper head of another electrically conductive rivet 32 extending through web 28 at the end thereof opposite from rivet 30. The rivet 32 engages, on the underside of the web, a link member 33 in the form of a strap which has its major portion bent upwardly parallel with the wall of the tube 18. This link member is also composed of material having good electrical conductivity but of a relatively low melting point, being fusible when the temperature to which it is subjected becomes greater than what is required for safety. I prefer to utilize for the link 33 a fusible alloy which will melt at a temperature of approximately 330 F. Thermostat 31 is designed to break contact when the tube temperature reaches approximately 290 F. It will be understood that these particular temperatures that are given are those which have been determined to be preferable as of the instant writing. I do not, however, claim these temperatures as part of the invention, the invention residing rather in the arrangement of and relationship established between the various parts to obtain certain actions at given temperatures, which temperatures may change as progress is made in hair treating compositions.

Connected in parallel with the resistance wire 20 and located above the plug 25 is the neon lam-p 34. This lamp is connected by a conductor 35 (insulated with an appropriate insulator) with the lower end cap 22 and by a second conductor 36, also similarly insulated, with the upper cap 24. The conductors pass upwardly at the side of the O plug in a notched passageway 25b, as can best be seen in FIG. 5. The lamp has in series with it the necessary resistor to control amperage.

The upper end of the tube 18 is closed by a cap member 38 which is preferably molded and of a translucent plastic material. The cap has the end portion 38a providing a gripping surface for the fingers, a heat deflector frame 38b and an insertable lower end portion 380, which is received within the upper end of the tube. The portion 38c is designed to press fit within the upper end of the tube and it will be noted particularly from FIG. 3 that it has a cutaway notch at 380! designed to receive the conductors 35 and 36 as they proceed upwardly past the upper surface of the plug 25. The press fit portion 380 of the cap serves to firmly bind the upper end of the fusible link 33 against the wall of the tube 18, thus establishing good electrical contact therebetween. In order to more securely fasten the handle 38 to the tube, portions of the tube can be struck into the handle in the usual fashion. This, however, is not shown as it plays no part in the present invention.

Returning now to the console itself, generally speaking the details thereof are disclosed in my aforementioned copending application so only so much of the console as necessary to explain the manner of functioning of the heating element is shown herein and will be described. Referring to FIG. 2, it will be seen that when the heating elements are inserted in their respective cavities 13 or 14, the lower nipple portions 18a thereof contact and engage the downwardly turned lips or flanges 39a on a conductor member 39 extending across the bottom of the console. This conductor element is connected with one side of the power circuit to which the plug 11 is connected. The other side of the power circuit is connected to a bus bar 40, also extending across the bottom of the console and having branch contacts 40a which extend across and underlie the ends of contact pins 23 and make firm electrical contact therewith.

In operation of the apparatus the console 10 is plugged into a conventional wall socket by the plug 11 and the switch 12 is turned on. In this condition, when a heating unit 15 is inserted in one of the cavities 13 or 14, electrical current can flow from the lower bus bar 43 and its branch 40a through the contact pin 23, from thence through the cap 22 to the resistance wire 20 up to the upper end cap 24. From theupper end cap 24 the current is conducted through the contact strip 29 through rivet 30 into and through the bimetal element 31 back through rivet 32 and to the fusible link 33. By virtue of being pressed into firm contact with the tube wall 18, link 33 conducts the current thereto and the current flows back down through the tube walls to the nipple 18a and into the conductor 3-9 through the tabs 39a in contact with the nipples 18a. Since the lamp 34 is in parallel with the circuit just described, it will be lighted at all times that the circuit is closed, thus indicating that power is being supplied to the heating unit and that it is in the process of being readied for use.

As the unit continues to heat, heat is stored in the ceramic core 21 and in the ceramic insulator 19. The core 21 actually heats to a much higher temperature than the tube or shell 18. The dead air space between the core 21 and the tubular wall reduces the rate at which the heat stored in the core is radiated to the wall. Therefore, while the unit is in the console, the core may be raised to a much higher temperature than the tube wall in order to store more heat. As the temperature of the core and body is increased by the. heating, the temperature in the vicinity of the bimetal element 31 will increase also. When the heat increases the temperature of the bimetal element 31 sufliciently, the element will deform in the known manner and break the contact with rivet 32. Thereupon, the lamp 34 will extinguish, indicating to the user that the heating unit is now ready for use.

In the event that for some unforeseen reason, the thermostat element 31 should fail to break the contact, heating will continue to a somewhat higher temperature. However, damage to the unit or the reaching of an excessive temperature is protected against by the fusible link 33, which as earlier noted, is capable of melting and thereby interrupting the circuit at undesirable higher temperatures. Another great advantage in the link is that it permits ready repair of a unit in which the thermostat has failed to fuse simply through the expedient of replacing the plug, thermostat and link assembly, while still retaining all the other components.

During the time that the heating units are being heated, the user will roll a lock of hair around a hair curl roller such as at 16, and clamp the hair around the roller with the clamp 17. Then the user withdraws the heating unit from the console and inserts it into the cavity in the roller. It should be noted that the roller has a thick end closure 16a closing the roller at the far end and that there is a flared opening at the open end to facilitate insertion of the heating unit. 'Outwardly protruding dimples 18b are formed on the tube wall, these serving to engage the inside of the roller to assist in holding the heating unit in place on the users head. In other words, the dimples or protrusions serve to increase the frictional grip of the roller on the heating unit and prevent over easy removal.

It should also be noted that the combination of the heating unit and roller construction, that is with the clbsed end 16a of the roller operating to close one end of the heated zone and the cap and plug of the heating unit closing the other end, there is maximization of the heat stored within the heating unit. The plug and cap minimize heat losses out of the other end. Thus substantially all heat is confined for radiation laterally between the ends outwardly through the apertures in the roller.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcornbinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

'1. A heating unit for curling hair comprising a tubular body of material having good heat conductivity,

a heat storing core positioned internally in and running lengthwise of said body,

an electrically conductive cap on said core at one end,

an electric resistance wire heating element wrapped on said core and having one end electrically connected with said cap,

a non-conductive plug element positioned in said body adjacent said one end of said core and having a socket on the side confronting said core which fits over and receives said cap,

means supporting the other end of said core and cooperating with said socket to center said core in said tube,

means providing an electrical terminal for connecting the other end of said heating element with an external source of power, and

electrical circuit means mounted on said plug element including a contact in said socket engaging said cap,

a conductor connected with said contact and proceeding to the side of the plug element opposite from said socket, and a normally closed thermostatic switch on said opposite side in series with said conductor and operable to open in response to heat generated by said element.

2. The combination as in claim 1 wherein said plug element is ceramic.

3. The combination as in claim 1 wherein the inner end of said socket is provided with a groove there'across, said contact comprising a resilient conductive strip anchored at one end in the base of the groove with the other end extending toward and out of the groove into engagement with said cap.

4. The combination as in claim 1 including handle means having a portion inserted in the end of said body opposite from the socket in the plug element and engaging said plug element to prevent its d-isassociation from said core.

5. The combination as in claim 1 wherein said body is composed'of electrically conductive material and including means electrically connecting said switch means with said body, said last mentioned means including a fusible link connected with the switch means and wedged between said plug element and said body.

References Cited by the Examiner UNITED STATES PATENTS 1,530,352

RICHARD M. WOOD, Primary Examiner. ANTHONY BARTIS, Examiner. 

1. A HEATING UNIT FOR CURLING HAIR COMPRISING A TUBULAR BODY OF MATERIAL HAVING GOOD HEAT CONDUCTIVITY, A HEAT STORING CORE POSITIONED INTERNALLY IN AND RUNNING LENGTHWISE OF SAID BODY, AN ELECTRICALLY CONDUCTIVE CAP ON SAID CORE AT ONE END, AN ELECTRIC RESISTANCE WIRE HEATING ELEMENT WRAPPED ON SAID CORE AND HAVING ONE END ELECTRICALLY CONNECTED WITH SAID CAP, A NON-CONDUCTIVE PLUG ELEMENT POSITIONED IN SAID BODY ADJACENT SAID ONE END OF SAID CORE AND HAVING A SOCKET ON THE SIDE CONFRONTING SAID CORE WHICH FITS OVER AND RECEIVES SAID CAP, MEANS SUPPORTING THE OTHER END OF SAID CORE AND COOPERATING WITH SAID SOCKET TO CENTER SAID CORE IN SAID TUBE, MEANS PROVIDING AND ELECTRICAL TERMINAL FOR CONNECTING THE OTHER END OF SAID HEATING ELEMENT WITH AN EXTERNAL SOURCE OF POWER, AND ELECTRICAL CIRCUIT MEANS MOUNTED ON SAID PLUG ELEMENT INCLUDING A CONTACT IN SAID SOCKET ENGAGING SAID CAP, A CONDUCTOR CONNECTED WITH SAID CONTACT AND PROCEEDING TO THE SIDE OF THE PLUG ELEMENT OPPOSITE FROM SAID SOCKET, AND A NORMALLY CLOSED THERMOSTATIC SWITCH ON SAID OPPOSITE SIDE IN SERIES WITH SAID CONDUCTOR AND OPERABLE TO OPEN IN RESPONSE TO HEAT GENERATED BY SAID ELEMENT. 